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Date:   Mon, 16 Sep 2019 23:07:35 +1000
From:   Matthew Bobrowski <mbobrowski@mbobrowski.org>
To:     Christoph Hellwig <hch@infradead.org>
Cc:     tytso@mit.edu, jack@suse.cz, adilger.kernel@dilger.ca,
        linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        david@fromorbit.com, darrick.wong@oracle.com
Subject: Re: [PATCH v3 1/6] ext4: introduce direct IO read path using iomap
 infrastructure
Message-ID: <20190916130735.GD4024@bobrowski>
References: <cover.1568282664.git.mbobrowski@mbobrowski.org>
 <532d8deae8e522a27539470457eec6b1a5683127.1568282664.git.mbobrowski@mbobrowski.org>
 <20190916120032.GA4005@infradead.org>
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On Mon, Sep 16, 2019 at 05:00:32AM -0700, Christoph Hellwig wrote:
> On Thu, Sep 12, 2019 at 09:03:44PM +1000, Matthew Bobrowski wrote:
> > +static bool ext4_dio_checks(struct inode *inode)
> > +{
> > +#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
> > +	if (IS_ENCRYPTED(inode))
> > +		return false;
> > +#endif
> > +	if (ext4_should_journal_data(inode))
> > +		return false;
> > +	if (ext4_has_inline_data(inode))
> > +		return false;
> > +	return true;
> 
> Shouldn't this function be called ext4_dio_supported or similar?

Yeah, let's run with your suggestion. I think 'ext4_dio_supported' reads far
better than what I've named this helper.
 
> Also bonus points of adding a patch that defines a IS_ENCRYPTED stub
> for !CONFIG_FS_ENCRYPTION to make this a little cleaner.

I like this idea and I will try to do this.

> Also the iomap direct I/O code supports inline data, so the above
> might not be required (at least with small updates elsewhere).

I did see this, but to be perfectly honest I haven't looked at what needs to
be done on the ext4 side of things to get it all plumbed up and working. I
wanted to get clear of these main bits and revisit after the fact within a
separate patch series.

--<M>--